I have been looking for a 700c clincher rimmed rear wheel to use on one of my 10-speed bikes (5-speed rear cogs) to replace the tubulars. I picked up a nice Shimano 105wheelset with 3-crossed 32s fronts and 36s rears and ($35 for both), with 700c Mavic rims. My rear dropout spacing is 120mm. The rear axle fits, but the problem is that my RD (Simplex SX-410) won't cover the six gears. I'm sure that if I could remove one of the cogs (i.e. make it a 5-speed) the RD would work fine. My question is, can I remove a cog and make it a 5-speed? I know that the Uniglide uses the smallest cog as a "lockring" and you remove it using two chain whips. Can I just remove the 2nd smallest gog and leave it at that, or do I need special spacers?
I've never had a RD come up short, but I guess it's possible. Are you sure you have the limit screws backed out all the way? Or maybe it's something funky about where the cable is anchored?
I'd start with making really sure that the RD actually is stroke limited. Back the limit screw all the way out, unhook cable, move by hand.
Removing a sprocket is a so-so suggestion. Particularly removing an intermediate sprocket may cause clunky shifting, as the chain now has to deal with a bigger step. Shortening a sprocket at either end is usually a safer bet, particularly if you're willing to add spacers.
Besides, assuming that the RD really is limited in stroke, unless you really want the smallest cog, why not just leave it as it is? So there will be one sprocket there that won't take the chain, so what? Whether you've got 5 or 6 sprockets there, you've still got 5 useable ones.
And I can't say that I've tried it but I wonder if the thread on the uni-glide body extends far enough to lock the sprockets in place if you were simply to remove one.
Thanks for the suggestions! My RD (Simplex SX410) just didn't have enough throw to cover the six gears in the cassette, even with the limit screws backed out. It got mighty close, but chattered trying to get onto the big cog (sometimes got there but slipped back under load). I disassembled the cassette, removed the 2nd smallest gog, took out the plastic spacer between it and the smallest (lockring) cog and put that spacer on the inboard side of the large cog. This allowed me to tighten everything up solid. More important, removing one of the cogs allowed me to get the axle to fit perfectly in the 120mm DO space without changing the chainline viz-a-viz the 5-speed freewheel... So it shifts fine and no RD adjustments are needed going between the original Maillard and Shimano 105 hubbed rear wheelsets.
This is my first experience with the 105/Uniglide freehub system, which I understand is obsolete. Too bad because I really like it.